/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.nexmark.queries;



import com.bff.gaia.unified.sdk.coders.Coder;

import com.bff.gaia.unified.sdk.coders.CoderException;

import com.bff.gaia.unified.sdk.metrics.Counter;

import com.bff.gaia.unified.sdk.metrics.Metrics;

import com.bff.gaia.unified.sdk.nexmark.model.Event;

import com.bff.gaia.unified.sdk.transforms.DoFn;

import com.bff.gaia.unified.sdk.transforms.ParDo;

import com.bff.gaia.unified.sdk.values.PCollection;



import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;



/**

 * Query 0: Pass events through unchanged. However, force them to do a round trip through

 * serialization so that we measure the impact of the choice of coders.

 */

public class Query0 extends NexmarkQueryTransform<Event> {

  public Query0() {

    super("Query0");

  }



  @Override

  public PCollection<Event> expand(PCollection<Event> events) {

    final Coder<Event> coder = events.getCoder();

    return events

        // Force round trip through coder.

        .apply(

        name + ".Serialize",

        ParDo.of(

            new DoFn<Event, Event>() {

              private final Counter bytesMetric = Metrics.counter(name, "bytes");



              @ProcessElement

              public void processElement(ProcessContext c) throws CoderException, IOException {

                ByteArrayOutputStream outStream = new ByteArrayOutputStream();

                coder.encode(c.element(), outStream, Coder.Context.OUTER);

                byte[] byteArray = outStream.toByteArray();

                bytesMetric.inc((long) byteArray.length);

                ByteArrayInputStream inStream = new ByteArrayInputStream(byteArray);

                Event event = coder.decode(inStream, Coder.Context.OUTER);

                c.output(event);

              }

            }));

  }

}